Difference between revisions of "If Command"
From GeoGebra Manual
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{{note| Derivative of '''If[condition, f(x), g(x)]''' gives '''If[condition, f'(x), g'(x)]'''. It does not do any evaluation of limits at the critical points.}} | {{note| Derivative of '''If[condition, f(x), g(x)]''' gives '''If[condition, f'(x), g'(x)]'''. It does not do any evaluation of limits at the critical points.}} | ||
==If Command in Scripting== | ==If Command in Scripting== | ||
− | + | If command can be used in scripts to perform different actions under certain conditions. | |
− | + | {{example|1= Let ''n'' be a number, and ''A'' a point. The command <code>If[Mod[n, 7] == 0, SetCoords[A, n, 0], SetCoords[A, n, 1]]</code> modifies the coordinates of point ''A'' according to the given condition. In this case it would be easier to use <code> SetCoords[A, n, If[Mod[n, 7] == 0,0,1]]</code>. | |
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− | {{example|1= Let ''n'' be a number, and ''A'' a point. The command <code>If[Mod[n, | ||
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}} | }} | ||
+ | Note that arguments of If must be Objects or [[Scripting Commands]], not assignments. Syntax <code>b=If[a>1,2,3]</code> is correct, but b=2 or b=3 would not be accepted as parameters of If. |
Revision as of 00:59, 3 December 2012
- If[ <Condition>, <Object> ]
- Yields a copy of the object if the condition evaluates to true, and an undefined object if it evaluates to false.
- If[ <Condition>, <Object a>, <Object b> ]
- Yields a copy of object a if the condition evaluates to true, and a copy of object b if it evaluates to false.
Warning: | Both objects must be of the same type. |
Conditional Functions
The If command can be used to create conditional functions. Such conditional functions may be used as arguments in any command that takes a function argument, such as Derivative, Integral, and Intersect.
Examples:
f(x) = If[x < 3, sin(x), x^2]
yields a function that equals sin(x) for x < 3 and x2 for x ≥ 3f(x) = If[x < 3 ∧ x>0, x^3]
yields a function that equals sin(x) for x between 0 and 3 and undefined for x ≥ 3 or x ≤ 0.
Note: See section: Boolean values for the symbols used in conditional statements.
Note: Derivative of If[condition, f(x), g(x)] gives If[condition, f'(x), g'(x)]. It does not do any evaluation of limits at the critical points.
If Command in Scripting
If command can be used in scripts to perform different actions under certain conditions.
Example: Let n be a number, and A a point. The command
If[Mod[n, 7] == 0, SetCoords[A, n, 0], SetCoords[A, n, 1]]
modifies the coordinates of point A according to the given condition. In this case it would be easier to use SetCoords[A, n, If[Mod[n, 7] == 0,0,1]]
.Note that arguments of If must be Objects or Scripting Commands, not assignments. Syntax b=If[a>1,2,3]
is correct, but b=2 or b=3 would not be accepted as parameters of If.